Evaluation of the "tilt test" in children

The "tilt test" (assessment of orthostatic pulse and blood pressure) is a non-invasive screening test for acute intravascular volume loss with well-accepted utility in the emergency evaluation of adults. Its value in children has been questioned because of reports of high false-positive rates. We report a prospective study to compare "tilt test" results between children with and without clinical volume depletion in a pediatric emergency setting. Children 4 to 15 years old seeking care at an urban pediatric emergency department were eligible. Children meeting the following criteria were classified as dehydrated: an acute history of vomiting or diarrhea and a volume depletion score greater than or equal to 4. The control sample was selected from children with minor complaints, and a volume depletion score less than 4. Blood pressure and heart rate were recorded at one-minute intervals by an automatic noninvasive blood pressure monitor for three minutes in the supine position. Subsequently, measurements were taken for two minutes in the standing position with the arm supported at heart level. Sixteen dehydrated and 21 normal children were enrolled; the groups were comparable in mean age, weight, sex, and oral temperature, but differed significantly in racial background. The mean orthostatic rise in heart rate was 29.1 beats per minute (+/- 10.7) in the clinically dehydrated group and 13.1 beats per minute (+/- 8.5) in the control group (P less than .001). There was no significant difference between the two groups with respect to the small decrease in systolic blood pressure (0.38 and 0.46 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)